SYNTHESIS AND EVALUATION OF ANTICANCER AND ANTIVIRAL ACTIVITY OF SOME 2-ARYL-3-(4-(2H-l-BENZOPYRAN-2-ONE-3-YL)-2-

THIAZOLYL)-5-METHYL-4-THIAZOLIDINONES

V. Rajeswar Rao*, P. Vijaya Kumar, V. Ravinder Reddy and K.M. Reddy Department of Chemistry, National Institute of Technology, Warangal - 506 004, A.P., India.

Email address : vrajesw@yahoo.com

Abstract: 2-Aryl-3-(4-(2H-l-benzopyran-2-one-3-yl)-2-thiazolyl)-5-methyl-4-thiazolidinones (3), have been prepared by the reaction of S c h i f f s bases (2) with 2-mercaptopropionic acid. The S c h i f f s bases in tum are obtained by the reaction of various aldehydes with 3-(2-amino-4-thiazolyl)coumarins. The compounds 3 have been evaluated for their anticancer and antiviral activity.

Introduction

The coumarin nucleus is found in a variety of natural products which exert varied

pharmacological effects. Numerous reports have appeared in the literature describing HIV

protease inhibiting, α-chymotrypsin inhibiting, analgesic, antimicrobial activity and

anticancer activity1"5 of 3-heterocyclyl coumarins. Further 4-thiazolidinone play a vital role

owing to their wide range of biological activities6"9 and industrial importance as stabilizers

for polymeric materials. The chemistry of the 4-thiazolidinone ring system was reviewed in

depth10. In order to explore the activities associated with both coumarin and thiazolidinone

rings, we report herein the synthesis and anticancer and antiviral activities of the new

derivatives of thiazolidinones.

In our ongoing search for potential anticancer agents we present our results on the

design of 2-aryl-3-(4-(2H-l-benzopyran-2-one-3-yl)-2-thiazolyl)-5-methyl-4-thiazoli-

dinones. The compounds presented here were assayed in vitro for their anticancer and

antiviral activity.

Reaction of 3-(2-bromoacetyl)coumarins with thiourea resulted in the formation of

3-(2-amino-4-thiazolyl)coumarins (1). Condensation of these compounds with various

aromatic aldehydes in presence of piperidine resulted in the Schiff bases 2. The Schiffs

bases on reaction with mercaptopropionic acid in dry benzene under reflux gave 3 (Scheme-

1). IR spectrum of 3 showed an intense peak at 1680 cm"1 indicating the presence of an

amide of thiazolidinone ring. The 3 has been identified as a diastereomeric mixture.

Compound 3h(i) and 3h(ii) are formed in the ratio of 54:46. The 'H NMR data given

confirm the diastereomeric excess to the extent of 8% in case of trimethoxy sunbstituted

thiazolidinone 3h(i) and 3h(ii). The absolute configuration of the diastereomers are

assigned tentatively11,12 on the basis of 'H NMR spectra as trans 2R, 5R(i) and cis 2R, 5S

(ii). 'H NMR spectra of 3h(i) and 3h(ii) showed two distinct doublets at δ 1.79 and 1.69 for

Vol. 1I, Nos. 3-4, 2005 Synthesis and evaluation of anticancer and antiviral activity of some 2-aryl-3-(4-(2H-1-benzopyran-2-one-3-yl)-2-thizaolyl

C5-CH3 of thiazolidinone ring and two distinct quartets at δ 4.20 and 4.35 for C5-H protons.

Similarly C2-H showed two independent singlets at 6.60 and 6.70. The product formation

was further supported by mass spectrum which showed molecular ion at m/z 510.

The diastereomeric mixture could not be resolved into individual diastereomers by

silica g el c hromatography b y using ν arious s olvent s ystems6'7. This i s due t o t heir ν ery

close proximity in their Rf values.

Experimental

All melting points were determined in open capillary tubes using sulphuric acid bath

and are uncorrected. IR Spectra (vmax in cm'1) were recorded in Perkin-Elmer - 282

instrument (USA), 'H-NMR spectra on varian 200 MHz spectrometer (Darmstudt,

Germany) using TMS as internal standard (Chemical Schifts in δ ppm) and mass spectra on

Jeol-JMS-D mass spectrometer at 70 eV.

The various derivatives of 3-(2-bromoacetyl)coumarins and 3-(2-amino-4-

thiazolyl)coumarins were prepared according to our earlier procedure13"14. Representative

methods of preparation of compounds 2 and 3 along with spectral data are described as:

Preparation of 3-(2-(Arylmethylene)amino-4-thiazolyl)-2H-l-benzo- pyran-2-one (2). A

mixture of 0.244 g (0.001 mol) of 3-(2-amino-4-thiazolyl)coumarin and aromatic aldehyde

(0.001 mol) was refluxed in ethanol containing catalytic amount of piperidine for 4 hours.

The reaction mixture was cooled and the separated solid was filtered and crystallized from a

suitable solvents to yield 2 in the pure form.

3-(2-(Arylmethylene)amino-4-thiazolyI)-2H-l-benzopyran-2-one (2a). IR (cm1) : 1600

(-C=N-), 1720 (-C=0), 3300-3600 (-OH). 'H NMR (CDCI3, δ ppm) : 6.9 (s, 1H,

methylene), 7.0-7.6 (m, 8H, aromatic), 8.3 (s, 1H, C5 of thiazole), 8.6 (s, 1H, coumarin C4),

9.1 (s, 1H, phenolic OH). MS : m/z 348, 315, 286, 256, 244, 216, 174, 43 (100).

3-(2-(2-o-Hydroxy aryl methyleneamino)-4-thiazolyl)-6-chloro-2H-l-benzopyran-2-one

(2i). IR (cm·1): 1610 (-C=N-), 1720 (-C=0), 3300-3600 (-OH), 'H NMR (CDCI3, δ ppm):

6.8 (s, 1H, -CH=), 7.0-8.0 (m, 7 H, A r-H), 8.4 (s, 1H, C5 of thiazole), 9.0 (s, 1 H, C4 of

coumarin), 9.8 (s, 1H, OH).

3-(2-o-Hydroxy methyleneamino)-4-thiazolyl)-6-bromo-2H-l-benzopyran-2-one (2k).

IR (cm'1) : 1600 (-ON-), 1720 (-C=0), 3600 (-OH). 'H NMR (CDCI3 + DMSO-d«) : 6.9

274

V.Rajeswar Rao et αί Heterocyclic Communications

(s, 1H, -CH=), 7.0-7.8 (m, 7H, Ar-H), 8.4 (s, 1H, C5 of thiazole), 9.2 (s, 1H, C4 of

coumarin), 11.9 (s, 1H, -OH).

Preparation of 2-aryl-3-(4-2H-l-benzopyran-2-one-3-yl)-2-thiazolyl)-5-methyl-4-

thiazolidinone, 3(i) and 3(ii). To a well stirred solution of SchifFs base 2 (0.001 mol) in

dry benzene (50 ml), 2-mercaptopropionic acid 0.1061 g (0.001 mol) was added. The

contents were refluxed for 6 hours. The reaction mixture was cooled. The separated solid

was washed with sodium bicarbonate and recrystallised from benzene to yield 3 as

diastereomeric mixture. The diastereomeric mixture could not be resolved into individual

diastereomers by silica gel chromatography.

(3a) R = R' = H, R" = 2-hydroxyphenyl (3b) R = R' = H, R" = 2-hydroxy, 3-methoxyphenyl (3c) R = R' = H, R" = 5-bromo, 2-hydroxyphenyl (3d) R = R' = H, R" «= 3,5-dibromo, 2-hydroxyphenyl (3c) R = R' = H, R" = 4-methoxyphenyl (3f) R = R' = H, R" = 4-N,N-dimethylaminophenyl (3g) R - R' - H, R" = 2-hydroxy, 6-nitronapthyl (3h) R = R' = H, R " « 3,4,5-trimethoxyphenyl (3i) R = H, R' = CI, R" = 2-hydroxyphenyl (3j) R = H, R' = CI, R" = 4-methoxyphenyl (3k) R = H, R = Br, R" = 2-hydroxyphenyl (31) R = H, R' = Br, RM = 4-N,N-dimethylaminophenyl (3m) R = H, R' = Br, R" = 4-methoxyphenyl (3n) R = R' = Br, R" = 2-hydroxyphenyl (3o) R = R' = Br, R" = 4-N,N-dimethylaminophenyl

Cis 2R, 5S

Scheme - 1

2-o-Hydroxy aryl-3-(4-2H-l-benzopyran-2-one-3-yI)-2-thiazolyI)-5-methyl-4-

thiazolidinone (3a). IR (cm 1 ) : 1610 (-C=N-), 1685 (-CONH-) and 1720 (-C=0). 3a(i) :

275

Vol. / / , Nos. 3-4. 2005 Synthesis and evaluation of anticancer and antiviral activity of some 2-aryl-3-(4-(2H-1-benzopyran-2-one-3-yl)-2-thizaolyl

'H NMR (CDCI3, δ ppm) : 1.70 (d, J = 6.8 Hz, CH3 of thiazolidinone), 4.1 (q, J = 6.8 Hz,

1H, C5 of thiazolidinone), 6.78 (s, 1H, thiazolidinone C2-H), 7.18-7.26 (m, 8H, ArH), 8.00

(s, 1H, C5' of thiazole), 8.20 (s, 1H, C4 of coumarin) and 9.6 (s, 1H, phenolic OH). 3a(ii) :

δ : 1.90 (d, J = 6.8 Hz, CH3 thiazolidinone), 4.50 (q, J = 6.8 Hz, C5-H of thiazolidinone),

7.30 - 7.40 (m, 8 ArH), 8.10 (s, 1H, C5' of thiazole), 8.30 (s, 1H, C4 of coumarin) and 9.6 (s,

1H, phenolic OH).

2-/7-N,N-Dimethylamino-3-(4-2H-l-benzopyran-2-one-3-yl)-2-thiazolyI)-5-methyl-4-

thiazolidinone (30- IR (cm·1) : 1590 (-C=N-), 1680 (-CON-), 1710 (-CO-). 3f(i) 'H NMR

(CDCI3, δ ppm): 1.70 (d, J = 6.8 Hz, CH3 of thiazolidinone), 2.9 (s, 6H, N(CH3)2), 4.1 (q, J

= 8 Hz, 1H, C5 of thiazolidinone), 6.5 (s, 1H, thiazolidinone C2-H), 6.60-6.70 and 7.20-7.58

(m, 8H, Ar-H), 8.10 (s, 1H, C5' of thiazole) and 8.30 (s, 1H, C4 of coumarin). 3f(ii) δ : 1.80

(d, J = 6.8 Hz, 3H, CH3 of thiazolidinone), 3.10 (s, 6H, N(CH3)2), 4.30 (q, J = 6.8 Hz, 1H of

thiazolidinone), 6.60 (s, 1H, thiazolidinone C2-H) and 7.45 - 7.58 (m, 8H, Ar-H), 8.18 (s,

1H, C5' of thiazole) and 8.50 (s, 1H, C4 of coumarin).

2-(3,4,5-Trimethoxyphenyl-3-(4-2H-l-benzopyran-2-one-3-yl)-2-thiazolyl)-5-methyl-4-

thiazolidinone (3h).

3h : IR (KBr, vmax cm·1) 1600 (-C=N-), 1680 (-CO-N-) and 1720 (-O-CO-).

3h (i) : 'H NMR (200 MHz) CDC13 δ; 1.69 (d, 3H, J = 6.8 Hz, thiazolidinone CH3), 3.85 (s,

9H, 3 χ OCH3), 4.20 (q, 1H, J = 6.8 Hz, thiazolidinone 5-H), 6.60 (s, 1H, C2-H of

thiazolidinone), 7.20-7.38 (m, 6H, Ar-H), 8.0 (s, 1H, C5' of thiazole) and 8.19 (s, 1H, C4 of

coumarin). 3h(ii) : 1.79 (d, 3H, J = 6.8 Hz, thiazolidinone CH3), 3.85 (s, 9H, 3 χ OCH3),

4.35 (q, 1H, J = 6.8 Hz, thiazolidinone 5-H), 6.65 (s, 1H, C2-H of thiazolidinone), 6.50-6.70

(m, 2H, Ar-H), 7.40-7.58 (m, 6H, Ar-H), 8.1 (s, 1H C5' of thiazole) and 8.20 (s, 1H, C4 of

coumarin). MS : m/z 510, 454, 421, 391, 289, 271, 244 and 211 (100%).

2-o-Hydroxy aryl-3-(6,8-dibromo-2H-l-benzopyran-2-one-3-yl)-2-thiazoIyI)-5-methyl-

4-thiazolidinone (3n).

IR (cm1) : 1610 (-C=N-), 1690 (-CON-) and 1720 (-CO-). 3n(i) : 'Η NMR (CDC13, δ

ppm) : 1.70 (d, J = 6.8 Hz, CH3 of thiazolidinone), 4.20 (q, J = 6.8 Hz, 1H of

thiazolidinone), 6.70 (s, 1H, C2-H of thiazolidinone), 7.20 - 7.38 (m, 6H, ArH), 8.0 (s, 1H,

C5' of thiazole), 8.20 (s, 1H, C4 of coumarin) and 9.60 (s, 1H, phenolic OH). 3n(ii) δ : 1.90

(d, J = 6.8 Hz, CH3 of thiazolidinone), 4.50 (q, J = 6.8 Hz, 1H of thiazolidinone), 6.90 (s,

276

I'. Rajeswar Rao el at. Heterocyclic Communications

1H, C2-H of thiazolidinone), 7.20 - 7.38 (m, 6H, ArH), 8.10 (s, 1H, C5' of thiazole), 8.20 (s,

1H, C4 of coumarin) and 9.60 (s, 1H, phenolic OH).

Biological Evaluation

The synthesized compounds were screened for their anticancer and antiviral

activities. Biological studies on 2-aryl-3-(4-(2H-l-benzopyran-2-one-3-yl)-2-thiazolyl)-5-

methyl-4-thiazolidinones 3a-3o were carried against murine leukemia cells and human T-

Lymphocyte cells and results are shown in Table - 1. The antiviral activity of 3a-3o were

carried out against varicella-zoster virus in human embryonic lung (HEL) cells. The

antiviral activities of these compounds are given in Table-2. The anticancer and antiviral

activity has been carried out at Rega Medical Research Institute, Luven, Belgium.

Anticancer Activity

It is evident from the results that there is in general good agreement between the

different murine and human cell lines. 3a, 3b, 3d and 3i were the most cytotoxic. However,

we believe that the cytotoxic activities are not sufficient pronounced for the compounds to

be considered for further persuit as antitumor leads. Most of the compounds of

thiazolidinones, except for 3h,31 and 3m also inhibited the proliferation of tumor cells i.e.

murine leukemia cells and human T-lymphocytic cells,with in the concentration range of

10-100 μg/ml. Their cytostatic activity did not vary significantly from one cell line to

another. When evaluated under the same conditions, melphalan exhibited cytostatic activity

with in the 0.5 -1.0 μg/ml concentration range.

The method15 used to measure cytostatic activity was as follows.

All assays were performed in 96 well microtiter plates (Falcon 3072; Becton

Dickinson , Paramus, NJ) . To each cell were added ca. 6xl04 murine leukemia L1210 , or

human lymphocyte molt 4/Cs and CEM cells (100 μΐ) and a given amount of the test

compound (100μ1) . The cells were allowed to proliferate for 48 to 72 h at 37°c in

humidified CO2 controlled atmospuere . At the end of the incubation period , the cells were

counted in a coulter counter (model ZB; coulter Electronics Ltd; Harpender, Hertfordshire,

England). 50% Cytostatic concentration (CC50) was defined as the concentration of

compound that inhibited cell proliferation by 50%.(Table-2)

277

Vol. 11, Nos. 3-4. 2005 Synthesis and valuation of anticancer and antiviral activity of some 2-ary!-3-(4-(2H-l-benzopyran-2-one-3-yl)-2-thizaolyl

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Antiviral Activity

Compounds 3e and compound 3k demonstrated a slight but selective activity against

CMV, with a selectivity index (SI) (or ratio of CC5o to IC50) of > 5. Compounds 3k and 3n

demonstrated s ome activity a gainst both Τ K+ and Τ Κ" strains ο f VZU with a SI r anging

from >4 to >12.5.From the series of thiazolidinones.the following showed an appreciable

activity against both thymidine kinase-encoding(TK+)and thymidine kinase-deficient (TK'

)VZV strains:3c,3d,3e,3f,3g,3j,3k and 3n ,albeit at concentrations that were in the best cases

not lower than a tenth of the minimum cytotoxic concentration. This means that even the

most specific compounds, i.e.3f,3k and 3n did not show a selectivity index greater than ten.

This contrasts with the activity shown by BVDU(brivudin) against TK+ VZV, which was

inhibited by BVDU with a selectivity of greater than 50,000.

Table-2 : Inhibitory effects of compounds on the proliferation of murine leukemia cells (LI 210/0) and human T-lymphocyte cells

(MOLT4/C8, CEM/0)

Compound IC50 ^ g / m l ) L1210/0 MOLT4/C8 CEM/0

3a 8.4 + 0.2 14 + 2 12 + 3

3b 6 1 + 7 99 ± 2 6 74 ± 2 0

3c 12 + 0 12 + 8 8.5 ± 3 . 2

3d 14 + 0 18 + 2 16 ± 3

3e 88 + 0 28 ± 13 47 ± 2

3f 88 + 1 25 ± 0 35 + 7

3g 83 + 2 38 + 9 38 ± 5

3h 152+15 180 ± 2 8 152 ± 5

3i 88 ± 3 75 ± 8 75 ± 5

3j 13 + 1 15 ± 1 1 0 + 1

3k 31 ± 4 22 ± 3 17 + 0

31 198 + 4 >200 >200

3m 186+19 146 ± 4 151 ± 17

3n 1 6 + 1 21 ± 4 16 + 2

3o 91 ± 7 70 ± 8 59 ± 3 50% inhibitory concentration

The method used to measure anti-VZV activity was as follows :

The activity of the test compounds against the laboratory wild-type VZV (varicella-

zoster virus) strains (Oka and Ys ) and the thymidine kinase-deficient VZV strains (0.7-

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land YS-R) was measured as previously described16. Briefly, confluent human embryonic

lung (HEL) fibro blasts grown in 96-well microtiter plates were inoculated with VZV at an

input of 20 plaque forming units (PFU) per well. After a 2h incubation period, residual virus

was removed and the infected cells were further incubated with medium containing variying

concentrations of the test compounds. After 5days ο f incubation, ν irus ρ laque formation

was determined and antiviral activity was expressed as 50%, inhibitory concentration

(IC50) or compound concentration required to reduce viral plaque formation by 50%

compared to the untreated control cytotoxicity was expressed as the 50% cytostatic

concentration (CC50),defined as the compound concentration required to inhibit cell growth

by 50%, and the MCC (minimae cytotoxic concentration), defined as the compound

concentration required to cause a microscopically detectable alteration of normal cell

morphology. (Table 3and 4)

Table-3 : Activity of compounds against varicella-zoster virus in human embryonic lung (HEL) cells

I ΛΤΠΠΛΙΙΠΜ Antiviral activity ^g/ml)a Cytotoxicity ^g /ml ) v_/UIIipUUIlU TK+VZV TK+VZV Cell morphology Cell growth (CC50)c

OKA strain 07/1 strain (MCC)b Cell growth (CC50)c

3a >2 >2 5 20 3b >5 >2 >5 32 3c 1.8 >2 >5 10.2 3d 2.9 4.5 20 9.3 3e 11 14 >50 >50 3f 3 10 >50 34

3g >5 11 >20 36 3h 46 50 >50 48 3i >5 >5 20 16.6

3j 1.5 >2 >5 17 3k 4 11 50 >50 31 39 27 >50 >50

3m >20 >5 >20 >50 3n 4 5 >20 >50 3o 23 30 >50 >50

ACV 0.44 50 >50 >200 BVDU 0.001 >50 >50 >200

'Inhibitory concentration required to reduce virus plaque formation by 50%. Virus input was 100 plaque forming units (PFU). bMinimum cytotoxic concentration that causes a microscopically detectable alteration of cell morphology. 'Cytotoxic concentration required to reduce cell growth by 50%

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Γ. Rajeswar Rao et al. Heterocyclic Communications

Table -4 : Activity of compounds against cytomegalovirus in human embryonic lung (HEL) cells

Antiviral activity IC50 (μβ/ιη!)" Cytotoxicity ^g/ml) Compound AD-169 strain Davisstrain Cell morphology Cell growth (CC5o)c

(MCC)b

3a >5 >2 > 5 20

3b >2 >2 5 32

3c >2 >2 5 10.2

3d 3 >0.5 20 9.3

3e 12 10 >50 >50

3f 10 10 >50 34

3g 10 10 50 36

3h >50 38 >50 48

3i >5 >5 20 16.6

3j >5 >5 20 17

3k 10 10 50 >50

31 >50 >50 >50 >50

3m >50 >20 >50 >50

3n >5 >5 20 >50

3o 35 33 >50 >50

DHPG 1.0 2.7 >50 >200

(S)-HPMC 0.3 0.9 >50 192 'Inhibitory concentration required to reduce virus plaque formation by 50%. Virus input was 100 plaque forming units (PFU). ''Minimum cytotoxic concentration that causes a microscopically detectable alteration of cell morphology. 'Cytotoxic concentration required to reduce cell growth by 50%

Acknowledgements

We thank the Director, NIT, Warangal for providing facilities to carry out this work.

The author PVK is grateful to UGC, New Delhi for the award of fellowship in the project.

Authors also thank Prof. G.L. David Krupadanam, Department of Chemistry, Osmania

University for helpful discussions.

References

1 S. Thiasrivangs, M.N. Janakiraman, T.K. Cheng, S. Wang, G.W.A. Milne, X. Yan, I.J. Posey, M.C. Nicklaus, L. Graham and W.G. Rice, J. Med. Chem. 39, 2047 (1996).

2 L. Pochet, C. Doucet, M. Schynts, L. Pochet, C. Doucet, M. Schynts, N. Thierry, N. Boggetto, Β. Pirotte, Y. Jiang, B. Masereel, P. de Tullio, J. Delarge and M. Reboud-Ravaux, J. Med. Chem. 39, 2579 (1996).

283

Vol. II. Nos. 3-4, 2005 Synthesis and evaluation of anticancer and antiviral activity of some 2-aryl-3-(4-(2H-l-benzopyran-2-one-3-yl)-2-thizaolyl

3 M.H.B. Mruthunjaya Swamy and K.B. Shanthaveerappa, Indian J. Chem. 39B, 433 (2000).

4 K.H. Sinnur, S. Siddappa, S.P. Hiremath and M.G. Purohit, Indian J. Chem. 25B, 894(1986).

5 K. Srimanth, V. Rajeswar Rao and R. Krishna Devarakonda, Arzheim Forsch. Drug Res. 52(5), 388 (2002).

6 S. Grasso, A. Chimirri, P. Monforte, G. Fenech, M. Zappalar and A.M. Monforte, Farmaco Ed. Sei., 43, 851 (1988); Chem. Abstr. 110, 50734C (1989).

7 V.K. Srivastava, S. Singh, A. Gulati and A. Shankar, Indian J. Chem. 26B, 652 (1987); Chem. Abstr. 108, 20458d (1988).

8 A.M. Fahmy, K.M. Hasson, A.A. Khalaf and R.A. Ahmad, Indian J. Chem., 268, 884 (1987); Chem. Abstr. 109, 92871e (1988).

9 M.A. Mahasafi, M.H. Meshkatisadat and H. Parekh, Indian J. Chem. 26B, 803 (1987); Chem. Abstr. 109, 6453r (1988).

10 G.R. Newkome and A. Nayak, Adv. Heterocycl. Chem. 25, 84 (1979).

11 S. Kanwar, A. Saluja, J.P.S. Khurana and Sharma, J. Indian Chem. Soc. 78, 138 (2001).

12 E. Rajanarendar, D. Karunakar and M. Srinivas, Indian J. Chem. 43B, 643 (2004).

13 V. Rajeswar Rao and T.V. Padmanabha Rao, Indian J. Chem. 25B, 413 (1986).

14 S. Ramanna, V. Rajeswar Rao, T. Surya Kumari and T.V. Padmanabha Rao, Phosphorous Sulfur and Silicon 107, 197 (1995).

15 E. Declercq, J. Balzarini, P.F. Torrence, M.P. Mertes, C.L. Schmidt, D. Shugar, P.J. Barr, A.S. Jones, G. Verhelst and R.T. Walker, Mol. Pharmacol. 19, 321 (1981).

16 G. Andrei, R. Snoeck, D. Reymen, C. Liesnard, P. Goubau, J. Desmyter and E. De Clereq, Microbiol. Infect. Dis. 14, 318 (1994).

Received on November 11, 2004

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